Search

Using the concept of transformative autonomy as a guide, this article speculates about the possibilities of it offering to develop a critical community psychology in education which strengthens education as a public good in South Africa's democracy. The speculations are cast against two sets of data, namely: primary school role players' narratives about the learner support offered and received in their contexts; and high school learners' understanding of Dewey's notion of the purpose of progressive education. These data sets were analysed using a qualitative appraisal of the psychopolitical validity of the responses. The parents, teachers and learners of two rural primary schools displayed psychopolitically valid understandings of learner support as their business first, before it is that of the government. The high school learners (in Grade 10 and 11) demonstrated, at least, epistemic psychopolitically valid understandings that progressive education should be for social transformation in a progressive direction. Higher education, by emphasising transformative autonomy during teacher education, can play a crucial role in framing education as a public good and for the furtherance of democracy. [ABSTRACT FROM AUTHOR]

The article discusses the different types of gastritides and gastropathies and their wide range of etiologies. The reason for the poor correlation between the clinical presentation and pathology in the upper gastrointestinal tract is presented. The difference between acute gastritis and chronic gastritis is explained. The types of gastritis and gastropathy discussed include among others acute hemorrhagic gastritis, helicobacter pylori gastritis, autoimmune gastritis and lymphocytic gastritis.

High-resolution rainfall data from two stations in the northern KwaZulu-Natal Drakensberg provide insight into the effect of altitude on individual rainfall event characteristics. The effect of altitude on the duration and erosivity (rainfall intensity and kinetic energy) of concurrent rainfall on the escarpment and in the foothills is analysed using 5-min interval data for the calendar year 2003. A cumulative total of 229 rainfall events, measured at the Royal Natal National Park station (1 392 m a.m.s.l.) and a temporary station on the escarpment at Sentinel Peak (3 165 m a.m.s.l.), were considered, of which 79 rainfall events were found to fall concurrently at the two stations. The data indicate that the concurrent events generate rainfall for longer on the escarpment, but that the amount of rain produced as well as the intensity at which it falls is less than that in the foothills, both in summer and winter. The escarpment appears to limit erosivity, with only 11 events meeting the set criteria for erosivity in the foothills but failing to meet the same criteria on the escarpment. This decrease in erosivity contrasts with previous models for the Drakensberg that demonstrate higher erosivity in the upper reaches, but concurs with studies in mountainous regions elsewhere which found that erosivity decreases with altitude. It is tentatively suggested that the difference in rainfall characteristics could be related to the sources of precipitation and the manner in which the escarpment zone affects the formation and distribution of rainfall. The paper also highlights the need for further research into the association between rainfall structure and synoptic conditions and the effect that the escarpment has on modifying large-scale rainproducing systems in the KwaZulu-Natal Drakensberg. [ABSTRACT FROM AUTHOR]

Inverse synthetic aperture radar (ISAR) imaging of sea vessels is a challenging task because their 3-D rotational motion over the coherent processing interval (CPI) often lead to blurred images. The selection of the duration of the CPI, also known as the coherent processing time window length (CPTWL), is critical because it should be short enough to limit the blurring caused by the 3-D rotational motion and long enough to ensure that the desired cross-range resolution is obtained. This paper proposes an algorithm, referred to as the motion-aided CPTWL selector (MACS) algorithm, which selects suitable CPTWLs for ISAR imaging of cooperative sea vessels. The suggested CPTWLs may be used to obtain motion-compensated ISAR images that have the desired medium cross-range resolution and limited blurring due to 3-D rotational motion. The proposed algorithm applied to measured motion data of three different classes of sea vessels: a yacht, a fishing trawler, and a survey vessel. Results show that longer CPTWLs are needed for larger vessels in order to obtain ISAR images with the desired cross-range resolution. The effectiveness of the CPTWLs, suggested by the MACS algorithm, is shown using measured radar data. The suggested CPTWLs may also be used to select an effective initial CPTWL for Martorella/Berizzi's optimum imaging selection algorithm when it is applied to measured radar data of small vessels. Lastly, the proposed technique offers significant computational savings for radar cross section measurement applications where a few high-quality ISAR images are desired from long radar recordings. [ABSTRACT FROM AUTHOR]

Rainfall intensity, kinetic energy and erosivity were analysed for 106 erosive storm events at five locations in the KwaZulu-Natal Drakensberg, from late 2001 to early in 2006. The stations cover an altitudinal range of 1060 m to 3165 m a.s.l. and provide the first detailed rainstorm data for the Drakensberg area. Erosive storm events, defined as total rainfall exceeding 12.5 mm and a maximum 5-minute intensity greater than 25mmh-1, are found to vary in duration and depth (total rainfall) with the distribution biased towards shorter, shallower storms. Erosive rainstorms are almost exclusively a summer phenomenon and the attributes of these storms (rainfall intensity, kinetic energy and erosivity) are positively correlated with rainfall depth, but not with storm duration. Inter-station similarities exist with respect to rainfall depths and mean kinetic energy from individual storm events. Altitudinal trends are, however, evident for storm maximum intensity, depths of erosive storms and cumulative kinetic energy. Together with frequency of erosive events and extent of collective erosive effects, all these rainfall attributes decrease with station altitude. Dissimilarities in cumulative kinetic energy and cumulative erosivity can be explained by the lack of erosive events during early and late summer on the escarpment and by significant erosive rains during this period at lower altitudes in the foothills. [ABSTRACT FROM AUTHOR]

The contents of the Cape Basin of the South Atlantic Ocean, southwest of Cape Town, is a melange of water types from a number of different sources. One of the least studied of these water types comes from intrusions of sub-Antarctic water that are associated with the spawning of Agulhas rings. An analysis of a variety of data on the region shows that these intrusions originate along a latitude of 40°S, but only between longitudes of 8° and 22°E. In extreme cases they can extend equatorward beyond the southern tip of Africa. Intrusions take place at least five times per year. Their distinct surface expressions are shown to be but outcrops of water masses that usually are found at greater depths. These vertical perturbations may extend to depths exceeding 1500 m. [ABSTRACT FROM AUTHOR]

Round Island is a 219 ha volcanic island that lies 22 km north of Mauritius. Reaching almost 300 m in altitude, the small island has steep slopes, thin soils and a rocky coast that dips steeply into the sea. In the past the island has been subjected to human influence through the introduction of alien species, including goats, rabbits and plants, severely degrading the floral and faunal ecology. Since being declared a Nature Reserve in 1957 the rehabilitation of the island has received international praise. However, extensive erosion remains problematic. Unusually, the island exhibits gully forms that extend deeply into the tuff bedrock. A modified version of the Southern African Regional Commission for the Conservation and Utilisation of the Soil (SARCCUS) erosion classification system was used to describe two such bedrock-incised gully networks, ‘camp’ and ‘big’ gully, based on morphometric parameters and erosion severity. Rock hardness was also assessed to determine lithological controls on bedrock-incised erosion features. The gullies have their starting points on the mid-upslope regions as rills. These increase in width and depth downslope to a very severe bedrock-gully erosion classification and an exit at sea level. The predominant rock type on Round Island is tuff which is a relatively weak volcanic rock, as indicated by low mean Schmidt Hammer R-values, implying higher expected bedrock erosion rates. During periods of intense rainfall the bedrock-incised gullies act as transport channels for sediment which is ultimately lost to sea. Rehabilitation efforts entail planting of indigenous species and mechanical soil traps on the slopes which has been effective, although localised. Natural re-vegetation has been occurring in the gully channels, particularly in the mid-sections of the gullies. The most appropriate steps toward rehabilitation should thus focus on the wide-scale establishment of vegetation, as it would appear that due to the extensive nature of gullies on Round Island and its steep topography, erosion is a natural phenomenon that is sensitive to human influence. [ABSTRACT FROM AUTHOR]

Here, we present and release the Global Rainfall Erosivity Database (GloREDa), a multi-source platform containing rainfall erosivity values for almost 4000 stations globally. The database was compiled through a global collaboration between a network of researchers, meteorological services and environmental organisations from 65 countries. GloREDa is the first open access database of rainfall erosivity (R-factor) based on hourly and sub-hourly rainfall records at a global scale. This database is now stored and accessible for download in the long-term European Soil Data Centre (ESDAC) repository of the European Commission's Joint Research Centre. This will ensure the further development of the database with insertions of new records, maintenance of the data and provision of a helpdesk. In addition to the annual erosivity data, this release also includes the mean monthly erosivity data for 94% of the GloREDa stations. Based on these mean monthly R-factor values, we predict the global monthly erosivity datasets at 1 km resolution using the ensemble machine learning approach (ML) as implemented in the mlr package for R. The produced monthly raster data (GeoTIFF format) may be useful for soil erosion prediction modelling, sediment distribution analysis, climate change predictions, flood, and natural disaster assessments and can be valuable inputs for Land and Earth Systems modelling., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Author(s).)

Chemical weathering is regarded as a "geological thermostat", affecting the global carbon cycle and long-term climate stability, and hydrochemistry of river is the important way to study weathering. The Heilong River (Amur River), as one of the largest rivers in the temperate/cool temperate zone, has received few studies on the chemical weathering rate and its contribution to the global carbon cycle in the entire Chinese section. This paper presents the hydrochemistry of river water, lake water, and groundwater from the arid upper reaches, the Greater Hinggan Mountains in the middle reaches, and the fluvial plain in the lower reaches of the Heilong River. TDS values range from 26.8 mg/l to 1141 mg/l with an average of 189 mg/l. The arid upper reaches are affected by strong evaporation and/or evaporite minerals dissolution, and the ion contents of some surface water and underground water exceed the quality standard for drinking water. Although the downstream flood plain area is highly industrial and agricultural, water chemistry shows that anthropogenic activities have not significantly deteriorated water quality. The chemical weathering rate of the small granitic and basaltic watersheds in the Heilong River Basin is within the lowest range in the world, which further demonstrates the control of climate factors on chemical weathering. The calculated CO 2 consumption flux from silicate weathering in the Heilong River Basin is from 82.3 × 10 9 to 196 × 10 9  mol/y, accounting for 0.95%-2.25% of the global consumption values with a proportion of area of ∼1.2%. Compared with other temperate/cool temperate rivers worldwide, it is comparable to the Yenisei River in Siberia, but much higher than the Ob River and Lena River in Siberia, Mackenzie River and Yukon River in North America., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

A method based on Sr, Nd and Pb multi-isotopic systems indicates that the different rock types (carbonate rock, basalt and black rock series) and sulfide deposits exposed in the Pearl River Basin show markedly different Sr, Nd and Pb isotopic characteristics. By establishing the mass balance equations of heavy metal content and isotope ratios, we use the inverse method to obtain the contribution that natural weathering of carbonate rocks, basalts and black rock series as well as the mining of sulfide deposits have on heavy metal content in riverbed sediments in the Pearl River Basin. Even though carbonate rocks constitute more than 60% of the exposed area in the upper reaches of the Pearl River Basin, this lithology only contributes 9% of the heavy metal content in sediments due to the relatively low content of heavy metals found in this rock type. Basalt weathering on average contributes 64% of the Cr content and 42% of the Ni content found in the sediments, while 53% of the Cd content is derived from the weathering of the black rock series. The negative impact mining has on this environment cannot be ignored as it is the most important source of As (71%) and Pb (60%) in all samples. This is especially the case in the Diaojiang River Basin, where sulfide mining activities still contribute more than 90% of the content of Zn, Pb, Cd and As within the sediments even though many mining sites have been closed since 2000., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Novel species of fungi described in this study include those from various countries as follows: Antartica , Cladosporium austrolitorale from coastal sea sand. Australia , Austroboletus yourkae on soil, Crepidotus innuopurpureus on dead wood, Curvularia stenotaphri from roots and leaves of Stenotaphrum secundatum and Thecaphora stajsicii from capsules of Oxalis radicosa. Belgium , Paraxerochrysium coryli (incl. Paraxerochrysium gen. nov.) from Corylus avellana. Brazil , Calvatia nordestina on soil, Didymella tabebuiicola from leaf spots on Tabebuia aurea, Fusarium subflagellisporum from hypertrophied floral and vegetative branches of Mangifera indica and Microdochium maculosum from living leaves of Digitaria insularis. Canada , Cuphophyllus bondii from a grassland. Croatia , Mollisia inferiseptata from a rotten Laurus nobilis trunk. Cyprus , Amanita exilis on calcareous soil. Czech Republic , Cytospora hippophaicola from wood of symptomatic Vaccinium corymbosum. Denmark , Lasiosphaeria deviata on pieces of wood and herbaceous debris. Dominican Republic , Calocybella goethei among grass on a lawn. France (Corsica) , Inocybe corsica on wet ground. France (French Guiana) , Trechispora patawaensis on decayed branch of unknown angiosperm tree and Trechispora subregularis on decayed log of unknown angiosperm tree. Germany , Paramicrothecium sambuci (incl. Paramicrothecium gen. nov.) on dead stems of Sambucus nigra. India , Aureobasidium microtermitis from the gut of a Microtermes sp. termite, Laccaria diospyricola on soil and Phylloporia tamilnadensis on branches of Catunaregam spinosa . Iran , Pythium serotinoosporum from soil under Prunus dulcis. Italy , Pluteus brunneovenosus on twigs of broadleaved trees on the ground. Japan , Heterophoma rehmanniae on leaves of Rehmannia glutinosa f. hueichingensis. Kazakhstan , Murispora kazachstanica from healthy roots of Triticum aestivum. Namibia , Caespitomonium euphorbiae (incl. Caespitomonium gen. nov.) from stems of an Euphorbia sp. Netherlands , Alfaria junci, Myrmecridium junci, Myrmecridium juncicola, Myrmecridium juncigenum, Ophioceras junci, Paradinemasporium junci (incl. Paradinemasporium gen. nov.), Phialoseptomonium junci, Sporidesmiella juncicola, Xenopyricularia junci and Zaanenomyces quadripartis (incl. Zaanenomyces gen. nov.), from dead culms of Juncus effusus, Cylindromonium everniae and Rhodoveronaea everniae from Evernia prunastri, Cyphellophora sambuci and Myrmecridium sambuci from Sambucus nigra, Kiflimonium junci, Sarocladium junci, Zaanenomyces moderatricis-academiae and Zaanenomyces versatilis from dead culms of Juncus inflexus, Microcera physciae from Physcia tenella, Myrmecridium dactylidis from dead culms of Dactylis glomerata, Neochalara spiraeae and Sporidesmium spiraeae from leaves of Spiraea japonica, Neofabraea salicina from Salix sp., Paradissoconium narthecii (incl. Paradissoconium gen. nov.) from dead leaves of Narthecium ossifragum, Polyscytalum vaccinii from Vaccinium myrtillus, Pseudosoloacrosporiella cryptomeriae (incl. Pseudosoloacrosporiella gen. nov.) from leaves of Cryptomeria japonica, Ramularia pararhabdospora from Plantago lanceolata, Sporidesmiella pini from needles of Pinus sylvestris and Xenoacrodontium juglandis (incl. Xenoacrodontium gen. nov. and Xenoacrodontiaceae fam. nov.) from Juglans regia . New Zealand , Cryptometrion metrosideri from twigs of Metrosideros sp., Coccomyces pycnophyllocladi from dead leaves of Phyllocladus alpinus, Hypoderma aliforme from fallen leaves Fuscopora solandri and Hypoderma subiculatum from dead leaves Phormium tenax. Norway , Neodevriesia kalakoutskii from permafrost and Variabilispora viridis from driftwood of Picea abies. Portugal , Entomortierella hereditatis from a biofilm covering a deteriorated limestone wall. Russia , Colpoma junipericola from needles of Juniperus sabina, Entoloma cinnamomeum on soil in grasslands, Entoloma verae on soil in grasslands, Hyphodermella pallidostraminea on a dry dead branch of Actinidia sp., Lepiota sayanensis on litter in a mixed forest, Papiliotrema horticola from Malus communis , Paramacroventuria ribis (incl. Paramacroventuria gen. nov.) from leaves of Ribes aureum and Paramyrothecium lathyri from leaves of Lathyrus tuberosus. South Africa , Harzia combreti from leaf litter of Combretum collinum ssp. sulvense, Penicillium xyleborini from Xyleborinus saxesenii , Phaeoisaria dalbergiae from bark of Dalbergia armata, Protocreopsis euphorbiae from leaf litter of Euphorbia ingens and Roigiella syzygii from twigs of Syzygium chordatum . Spain , Genea zamorana on sandy soil, Gymnopus nigrescens on Scleropodium touretii, Hesperomyces parexochomi on Parexochomus quadriplagiatus, Paraphoma variabilis from dung, Phaeococcomyces kinklidomatophilus from a blackened metal railing of an industrial warehouse and Tuber suaveolens in soil under Quercus faginea. Svalbard and Jan Mayen , Inocybe nivea associated with Salix polaris. Thailand , Biscogniauxia whalleyi on corticated wood. UK , Parasitella quercicola from Quercus robur. USA , Aspergillus arizonicus from indoor air in a hospital, Caeliomyces tampanus (incl. Caeliomyces gen. nov.) from office dust, Cippumomyces mortalis (incl. Cippumomyces gen. nov.) from a tombstone, Cylindrium desperesense from air in a store, Tetracoccosporium pseudoaerium from air sample in house, Toxicocladosporium glendoranum from air in a brick room, Toxicocladosporium losalamitosense from air in a classroom, Valsonectria portsmouthensis from air in men's locker room and Varicosporellopsis americana from sludge in a water reservoir. Vietnam , Entoloma kovalenkoi on rotten wood, Fusarium chuoi inside seed of Musa itinerans , Micropsalliota albofelina on soil in tropical evergreen mixed forests and Phytophthora docyniae from soil and roots of Docynia indica. Morphological and culture characteristics are supported by DNA barcodes. Citation : Crous PW, Osieck ER, Jurjević Ž, et al. 2021. Fungal Planet description sheets: 1284-1382. Persoonia 47: 178-374. https://doi.org/10.3767/persoonia.2021.47.06., (© 2021 Naturalis Biodiversity Center & Westerdijk Fungal Biodiversity Institute.)

Land-use/land-cover (LULC) changes have implications for the long-term outlook of environmental processes, especially in the face of factors such as climate change. These changes can have serious consequences for humans. In this study, remote sensing and geographic information system methods were used to investigate LULC changes in a critical biodiversity area (CBA) in the northern sections of Limpopo Province in South Africa from 1990 to 2018 using data obtained from the South African National Land Cover project. In 1990, the dominant land cover comprised thickets and dense bush, followed by woodland and built-up areas, covering proportions of 40, 24 and 18% of the total land-cover area, respectively. Bare and forest areas were the least dominant classes during this time. In 2018, the dominant land cover was woodland, followed by built-up areas, comprising 71 and 20% of the total area, respectively. Subsistence agriculture is a land-cover class with a relatively higher area compared to water bodies, wetlands and other classes. Between 1990 and 2018, significant changes in land-cover were noted for thickets and dense bush, woodland, water bodies, subsistence agriculture and built-up areas. Woodland increased by over 1000 hectares (ha) per year, while thickets decreased by over 900 ha per year. Interviews were conducted with local residents to determine what they thought were the drivers behind the observed changes. According to these interviews, the drivers included deforestation, agricultural activities in wetlands, sand and gravel mining, among others. The study's outcomes are critical for future land-use planning exercises and the long-term conservation of this CBA, an area rich in biodiversity and a strategic water source for the communities.

An order, family and genus are validated, seven new genera, 35 new species, two new combinations, two epitypes, two lectotypes, and 17 interesting new host and / or geographical records are introduced in this study. Validated order, family and genus: Superstratomycetales and Superstratomycetaceae (based on Superstratomyces ) . New genera: Haudseptoria (based on Haudseptoria typhae ); Hogelandia (based on Hogelandia lambearum ); Neoscirrhia (based on Neoscirrhia osmundae ); Nothoanungitopsis (based on Nothoanungitopsis urophyllae ); Nothomicrosphaeropsis (based on Nothomicrosphaeropsis welwitschiae ); Populomyces (based on Populomyces zwinianus ); Pseudoacrospermum (based on Pseudoacrospermum goniomae ). New species: Apiospora sasae on dead culms of Sasa veitchii (Netherlands); Apiospora stipae on dead culms of Stipa gigantea (Spain); Bagadiella eucalyptorum on leaves of Eucalyptus sp. (Australia); Calonectria singaporensis from submerged leaf litter (Singapore); Castanediella neomalaysiana on leaves of Eucalyptus sp. (Malaysia); Colletotrichum pleopeltidis on leaves of Pleopeltis sp. (South Africa); Coniochaeta deborreae from soil (Netherlands); Diaporthe durionigena on branches of Durio zibethinus (Vietnam); Floricola juncicola on dead culm of Juncus sp. (France); Haudseptoria typhae on leaf sheath of Typha sp. (Germany); Hogelandia lambearum from soil (Netherlands); Lomentospora valparaisensis from soil (Chile); Neofusicoccum mystacidii on dead stems of Mystacidium capense (South Africa); Neomycosphaerella guibourtiae on leaves of Guibourtia sp. (Angola); Niesslia neoexosporioides on dead leaves of Carex paniculata (Germany); Nothoanungitopsis urophyllae on seed capsules of Eucalyptus urophylla (South Africa); Nothomicrosphaeropsis welwitschiae on dead leaves of Welwitschia mirabilis (Namibia); Paracremonium bendijkiorum from soil (Netherlands); Paraphoma ledniceana on dead wood of Buxus sempervirens (Czech Republic); Paraphoma salicis on leaves of Salix cf. alba (Ukraine); Parasarocladium wereldwijsianum from soil (Netherlands); Peziza ligni on masonry and plastering (France); Phyllosticta phoenicis on leaves of Phoenix reclinata (South Africa); Plectosphaerella slobbergiarum from soil (Netherlands); Populomyces zwinianus from soil (Netherlands); Pseudoacrospermum goniomae on leaves of Gonioma kamassi (South Africa); Pseudopyricularia festucae on leaves of Festuca californica (USA); Sarocladium sasijaorum from soil (Netherlands); Sporothrix hypoxyli in sporocarp of Hypoxylon petriniae on Fraxinus wood (Netherlands); Superstratomyces albomucosus on Pycnanthus angolensis (Netherlands); Superstratomyces atroviridis on Pinus sylvestris (Netherlands); Superstratomyces flavomucosus on leaf of Hakea multilinearis (Australia); Superstratomyces tardicrescens from human eye specimen (USA); Taeniolella platani on twig of Platanus hispanica (Germany), and Tympanis pini on twigs of Pinus sylvestris Crous PW, Hernández-Restrepo M, Schumacher RK, Cowan DA, Maggs-Kölling G, Marais E, Wingfield MJ, Yilmaz N, Adan OCG, Akulov A, Álvarez Duarte E, Berraf-Tebbal A, Bulgakov TS, Carnegie AJ, de Beer ZW, Decock C, Dijksterhuis J, Duong TA, Eichmeier A, Hien LT, Houbraken JAMP, Khanh TN, Liem NV, Lombard L, Lutzoni FM, Miadlikowska JM, Nel WJ, Pascoe IG, Roets F, Roux J, Samson RA, Shen M, Spetik M, Thangavel R, Thanh HM, Thao LD, van Nieuwenhuijzen EJ, Zhang JQ, Zhang Y, Zhao LL, Groenewald JZ (2021). New and Interesting Fungi. 4. Citation: Crous PW, Hernández-Restrepo M, Schumacher RK, Cowan DA, Maggs-Kölling G, Marais E, Wingfield MJ, Yilmaz N, Adan OCG, Akulov A, Álvarez Duarte E, Berraf-Tebbal A, Bulgakov TS, Carnegie AJ, de Beer ZW, Decock C, Dijksterhuis J, Duong TA, Eichmeier A, Hien LT, Houbraken JAMP, Khanh TN, Liem NV, Lombard L, Lutzoni FM, Miadlikowska JM, Nel WJ, Pascoe IG, Roets F, Roux J, Samson RA, Shen M, Spetik M, Thangavel R, Thanh HM, Thao LD, van Nieuwenhuijzen EJ, Zhang JQ, Zhang Y, Zhao LL, Groenewald JZ (2021). New and Interesting Fungi. 4. Fungal Systematics and Evolution 7: 255-343. doi: 10.3114/fuse.2021.07.13., (© 2021 Westerdijk Fungal Biodiversity Institute.)

This paper investigates the dynamics between basalt weathering and heavy metal accumulation through a comparative study of 37 small basaltic watersheds within different climate zones in the Yungui (the Pearl River Basin in southwest China), Xuyi (the Huaihe River Basin in east China) and Leiqiong regions (Hainan Island in south China). From a comprehensive sampling regime of stream water, riverbed sediments and bedrock, this study shows that the concentrations of heavy metals in river water are far below the national surface water quality standard and WHO quality standard for drinking water, indicating no significant ecological risk for water body in these basaltic areas. In contrast, the riverbed sediments exhibit varying degrees of heavy metal enrichment in the process of weathering from bedrock to sediments: without enrichment for Cr, Ni, Cu and Zn, but significant enrichment for Cd, As and Pb. Cd exhibits the largest ecological risk of all the heavy metals in the basaltic watersheds especially in the Yungui region, which can be mainly attributed to the high geological background values in this area. Comparative studies of some major basalt watersheds in the world show that temperature, runoff and elevation differences significantly affect the chemical weathering rates and thus the accumulation of heavy metals., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Species of Raffaelea ( Ophiostomatales : Ascomycota ) are obligate symbionts of ambrosia beetles, some of which pose a substantial threat to forest trees. Leucaena leucocephala is a small mimosoid tree species that is considered as an invasive weed in most of its introduced range globally. During a field expedition on the French island of Réunion, dying L. leucocephala trees were observed. Samples were taken from these trees and isolations made from symptomatic wood tissues that included beetle tunnels, but in the absence of the beetles themselves. Multiple isolates of a fungus resembling a Raffaelea species were obtained from the discoloured wood associated with the beetle tunnels. To determine their identity, microscopic examination was performed and DNA sequences for three gene regions (ITS, LSU, TUB ) were obtained. Phylogenetic analyses based on these gene regions revealed that the isolates represent a new species of Raffaelea , described here as R. borbonica sp. nov. A pathogenicity test was conducted with the fungus, which was shown to cause lesions on the inoculated seedlings, but with a low level of aggressiveness., (© 2020 Westerdijk Fungal Biodiversity Institute.)

This paper presents the heavy metal content in river water, sediment and bedrock in the karst area of the Pearl River Basin in China to evaluate the long-term impact of natural weathering and mining on the ecological environment. The results show that Cd and As is 2-3 times more enriched within the carbonate bedrock of the Pearl River Basin compared to the upper continental crust (UCC), which is indicative of high geological background values. Within the river water of the upper reaches of the Diaojiang River (a tributary of the Pearl River), which flows through the Dachang super-large orefield, Zn, As, Cd and Sb exceeds the environmental quality standards for surface water (WQS) by more than an order of magnitude. Among these, Zn and Cd sharply decreases to within the WQS in the lower reaches of the river, but the content of As and Sb in the estuary is still several times higher than the WQS. Cd in the sediments of the small carbonate watersheds and in the mainstream of the Pearl River only present a low-moderate ecological risk. In contrast, severe heavy metal pollution of the sediments of the Diaojiang River Basin is observed. Even in the lower reaches, remote from the mining area, the content of Pb, Zn, As and Cd in the sediments is still two orders of magnitude higher than the soil background values. The content of both Cd and As presents a very high ecological risk, indicating that under the cumulative effect of high geological background values and mining, full restoration of the ecological environment in the Diaojiang River Basin is a complex and long-term process., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)